questionswhat class sd memory card is best?


First off the class is how many Mb/second can be transferred.. so Class 2 SD cards have write speeds of 2 MB per second. Class 4 is 4 Mbps. Class 6 is 6 Mbps, and Class 10 is 10 Mbps, so on and so forth...

you only need a high class for camcorders and digital audio recorders, where audio or video is written in real time.

If youre just storing/xfering data than a class 2 is fine... but I would recommend a class 6 or above for video


Agreeing with the above. 2 is fine for photos / music, 6 is probably alright for video with 10 being a bit better.

That being said, not all cards are created equal. It is not just the speed you want to check, but also the manufacturer. When it comes to cards, Sandisk seems to be well-loved by Nook Color modders due to the random write speeds. I have had pretty good luck with a PNY class 10 I got from Costco to use for data, but it isn't good at all for running an OS off of. (This due to the random writes.) Once you decide the size, and the class, you may want to check for benchmarks. Even once you get the card, you may want to use CrystalDiskMark (free benchmark tool) to get some info on the card. Also, make sure you are going through a reputable dealer. Some sites / sellers on eBay may try to sell you a knockoff card that either isn't up to spec, or isn't the claimed capacity. If it seems too good to be true and it isn't on here...


@devexityspace: Just curious, why would you need above 2Mb/s for audio? 512 kb/s is considered awesome sampling and only 1/4 of the bandwidth of a class 2 card. Unless I am missing something.


Personally, I will only purchase a class 10 or better. Even if it is only for pictures or audio. Now the reason is not because you actually need that speed for those items (because you certainly do not). But like most people, I am flat out impatient. Have you tried filling up an entire 16gb class 2 SD card with music? It takes forever to transfer. That takes over 2 HOURS!! to fill the card.

So necessary speed aside, I choose a class 10 SD because a class 10 SD card transfers normally between 30-45megs a second, not 2. (The class DOES NOT indicate the speed like others have said by the way, each class and brand has different speeds, 2 different brands of class 6 for example could be completely different speeds)

So a class 2 16gb SD card on average takes you over 2 hours to transfer a full 16gb to it. Were as a Class 10 card on average takes betwee 6-9 minutes to transfer the full 16gb over to it.

Its a matter of patience and convenience.


@themanoflegend: I agree with the comments on the class rating systems. I'd also like to add that a fast write speed would be recommended if you're going to be shooting HD video or do a lot of continuous shooting with a fast DSLR + lens. Something like what @iggz suggests above or the even faster

if your device supports it. Yes, it will be more costly than a slower rated card, but like I said, depending upon your usage/hardware the extra cost may be worth it.


Thank you all for such well thought out responses!

@devexityspace: So what you are saying is that, while recording, say, a video image, that a higher class rating is desirable (minimum 6), but that once captured, that it could be stored on any class card, minimum 2. Is that correct?

@apfrehm: I am so glad you mentioned that, as others may read this thread, and there is a big problem on eBay (and other sites I am sure) with bootleg flash drives and memory cards. I just mentioned this myself, the other day, on a deal posting. I will probably go with sandisk, from a reputable dealer, of course. Thanks for the site, I just scoped it out and it looks helpful.


@themanoflegend: I had gleaned from other sources, that class rating was not uniform across all cards/manufacturers. As far as the patience thing, I tend to do other stuff as I transfer data, so the cost may be more of an issue, for me.

@iggz: That looks great for other applications( I put it on my wish list), but in this instance I am looking at micro cards only, for use across several devices.


An addendum question:
Would it be better to have music spread out on several smaller capacity cards, or just go for broke an load a large cap. card or two? I am thinking of the inevitable failure of the card itself, and maybe not putting all my eggs into one basket, so to say.


@pickypickypicky: I would recommend one large card, because it will be much more convenient.

As with any data: if it's important enough to have, it's important enough to back up. JUST DO IT.


@themanoflegend: The class actually does correspond to r/w speed, but there's nobody who checks on the manufacturers' specs, so they can claim whatever they want. In general, a card from Sandisk or PNY will have speeds better than the stated class, where a brand like Transcend will be MUCH worse.


You need to find out the max speed your actual device can read/write at really


Class 4 memory card is all about its quality not at all mbps


Class are not about Mbps it's all about matter it's class1,2,3or4 it's all about quality